I don't know why people think they'll get modded for telling us how to unlock Mercenaries stuff. I've seen videos of gameplay for the full campaign, all Mercenaries levels including some of the secret boss enemies, every single costume that is currently available or that will be available in the near future...every aspect of the game. And of course I'm talking about the full retail version here, not Gamescom, PAX, or other event demos.

I always thought you unlocked Mercenaries stuff through the campaign but I've also been hearing that you unlock them through getting A and S ranks in Mercenaries. I'd really like to know for sure because it's a drag being forced to go through the campaign just to unlock Mercenaries stuff. I don't even know if there's an SS rank anymore.

Play the campaigns to unlock some characters and all stages. Get Grade B on a mercenary level to unlock that character's partner and get Grade A with any character to unlock a costume. Don't quote me on any of this, though.---PSN: Lazuri65XBL:LazuriXIII

For a more precise answer.Play all 3 campaigns to unlock all 3 merc maps.Get A to unlock costumes, getting an A with Leon will unlock his costume, Getting A with Sherry will unlock hers ect.Get A to unlock the 3 partners (Helena, Piers, Sherry)

But you need to get atleast one A on each map to unlock each character.Urban Chaos unlocks Helena, The ice cavern unlocks Sherry and the last unlock Piers.

Not sure about getting S' but i'm assuming getting an S with every character will unlock Hunk or Ada Wong.---Daniel Bryan is my future husband!http://24.media.tumblr.com/tumblr_m4rxpltQhL1qgvr4ko1_250.gif